Edge feed transport system for document sorting and stacking

ABSTRACT

The invention pertains to a document transport and sorting system utilizing an edge feed concept for transporting documents, one at a time, on unique document carriers, from a loading station to a plurality of unloading stations. At the unloading stations the documents are removed from the transport means and selectively deposited in a plurality of stackers.

United States Patent Jakubowski [45] Feb. 29, 1972 [54] EDGE FEED TRANSPORT SYSTEM FOR DOCUMENT SORTING AND STACKING [72] Inventor: Marek Jakuhowski, Endwell, N.Y.

[73] Assignee: International Business Machines Corporation, Armonk, NY.

[22] Filed: Apr. 17, 1970 [21] Appl.No.: 29,599

[52] U.S.Cl. ..l98/38, 271/79 [51] Int. Cl ..B65g 43/00 [58] Field ofSearch................271/79, DIG. 10; 198/38, 134;

[56] References Cited UNITED STATES PATENTS 3,318,435 3/1966 Scott 198/38 3,059,753 10/1962 Lisinski ..198/38 3,312,358 4/1967 Atanasof et al 198/38 FOREIGN PATENTS OR APPLICATIONS 554,229 3/1958 Canada ..2 l4/l M Primary Examiner-Even C. Blunk Assistant Examiner-Hadd S. Lane Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT The invention pertains to a document transport and sorting system utilizing an edge feed concept for transporting documents, one at a time, on unique document carriers, from a loading station to a plurality of unloading stations. At the unloading stations the documents are removed from the transport means and selectively deposited in a plurality of stackers.

11 Claims, 10 Drawing Figures PATENIEDFEB 29 I972 SHEET 1 OF 5 INVENTOR MAREK JAKUBOWSKI Su Aflu lutf! I 7 14' au 1 -L mK ATTORNEYS PATENTEDFEB29 I972 SHEET 2 BF 5 FIG.2

PAIENTEDFEB29 I972 3, 645,378

sum 3 OF 5 FIG 4a EDGE IFEIED TRANSPORT SYSTEM IFOR DOCUMENT SORTING AND STACITING BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is in the field of document transport and sorting systems which may be used with automatic document sorting apparatus.

2. Description of the Prior Art Modern business generates extensive amounts of paper documents much of which must be sorted for future processing. With the steady increase in the volume of these paper documents, it is clear that automatic sorting machines have become a necessity. There is no place in todays world where automatic sorting machines are more of a must than in the handling of mail. For example, the U.S. mail must be initially sorted as to State and City, and then further sorted down to individual carrier routes when the route is sequenced. What is required is an automatic transport and sorting machine capable of rapid, reliable handling of large numbers of envelopes of varying sizes.

One type of prior document transport system is the serial feed transport. Transports of this type carry documents at speeds which are a function of the document size. Mathematically this relationship is expressed as:

V, N X L/60 inches per second where:

V, document transport speed N machine throughput in documents per minute" L the distance between the leading edges of the documents.

Another prior document transport system is one which carries documents suspended from carriers which are mounted on an endless belt, the carriers being positioned transverse to the direction of movement of the belt. This system has the advantage that documents are carried at speeds independent of their size. In such systems, the document transport speed can be determined mathematically by the equation:

V, N X p/60 inches per second where: consists a phenolic bushings to the rod are at least two springsteel clips 50 which will serve to hold l document transport speed N the machine throughput in documents per minute p spacing between document carriers.

Since the value of p is much smaller thin L, for processing an equal number of documents, the use of the second system allows for a reduction in speed of the transport system. Speed reduction is important since the probability of document damage increases with the transport speed.

SUMMARY OF THE INVENTION This invention relates to a unique document transport and sorting system of the type which carries documents suspended from carriers which are attached to, and positioned transverse to the direction of movement of the transport system. The system developed and disclosed can handle documents at the rate of approximately 2,000 documents per minute with a transport speed of from -30 inches per second.

In operation, documents are placed in a document feed hopper, then separated one at a time by a separator, the separator feeding the documents to carriers of the transport means. Selectors under the control of either automatic or manual means, selectively release the document carriers over stackers. Unloading rollers at unloading stations withdraw the documents from the carriers and feeds them to the stackers. After the documents have been sorted, they may be removed from the stackers for further processing.

The document carriers, which will be more fully described below, are designed to reliably carry documents of varying lengths and widths. Each carrier is attached to an endless belt by a hinge and a latch means coupled to a carrier mounting plate which is attached to the endless belt. As the carrier sweeps by a loading station, documents which are traveling in a serial mode are placed into the carriers by means of a document separator which will be fully described below.

The loaded carriers move in succession over a series of unloading stations. Associated with each unloading station is a stacker for receiving the documents. When a carrier, carrying a document, arrives over an unloading station corresponding to its destination stacker, a carrier latch is tripped. The carrier, under the control of a hinge means, swings down under the force of gravity, and engages the lower edge of the document into unloading rollers of the unloading station. The unloading rollers withdraw the document from the carrier and present it to the stacker. The use of unloading rollers as opposed to allowing the documents to drop unaided into the stackers helps prevent document damage and assures proper stacking of the documents. Documents withdrawn from the carriers are stacked at a linear speed sufiiciently low (less than 70 inches per second) to avoid document edge damage from impacts with the stackers. At velocities above 70 inches per second, documents begin to suffer damage when they strike metal or other hard surfaces.

In addition, the use of the unloading stations alleviates the adverse effects of static electricity and the flow of air on the stacking process. Static electricity often causes documents to remain in a carrier after the carriers document holding mechanism is released. The force of the unloading rollers on the document effectively overcomes the force due to static electricity. Also, were it not for the unloading stations, a document release from a carrier might be caught in a flow of air and directed away from the stacker. By feeding the documents directly to the unloading stations, this latter problem is also overcome.

The system and its operation will become more apparent when discussed in relation to the preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a representation of a document feed hopper and the front view of the separator used with this invention;

FIG. 2 is a top view of the separator shown in FIG. 1;

FIG. 3 is a detailed representation of the unique carrier which is used with this invention;

FIG. 4a is a view of the carrier of FIG. 3 in relation to the carrier mounting plate with the carrier in an unlatched position;

FIG. 4lb is a view of the latch end of the carrier of FIG. 3 shown in relation to the carrier mounting plate;

FIG. 5 is a drawing of the transport means, unloading stations and stackers;

FIG. 6a shows the interposer side of the carrier selector disc;

FIG. 6b shows the set-reset side of the carrier selector disc;

FIG. 7 shows the details of the unloading stations; and

FIG. 8 shows a sorter control unit which may be used with this invention.

DETAILED DESCRIPTION OF THE PREFERRED. EMBODIMENTS To aid in the understanding of the invention, the document transport and sorting system will be broken down into its six basic components. These are:

l Document feed hopper,

2. Separator,

3. Document transport,

4. Selector,

5. Stackers,

6. Unloading stations.

Each one of these separate components will be described in detail in the following description of the preferred embodi ment of the invention.

The document feed hopper A continuous loading document hopper may be used. This will eliminate the necessity for feed interruptions while the hopper is being loaded. A diagrammatic representation of a hopper which is suitable for use with this invention is shown in FIG. 1.

The feed mechanism consists of a number of push gates 12. When a batch of documents, for example letters, are inserted into the hopper, gates 12 are released and driven via a fast traverse belt 20 until they come into contact with the back end of the inserted batch of letters. The gates 12, under the control of the feed belt 21, move the documents along the hopper presenting them to a separator face plate 14. The feed belt 21 may be driven by any suitable means.

When all of the documents which have been placed between the separator face plate 14 and the gates 12 have been fed into a transport means (to be described later), the gates 12 are withdrawn downwards into slots and returned to the end of the hopper, ready for a next batch of letters. It is understood by those skilled in the art that this is but one hopper which can be used. Other hoppers known in the art may also be used.

The separator A separator, designated 18 and shown generally in FIG. 1 and in detail in FIG. 2, provides means for transporting the documents located in the hopper to a transport means to be described. The rate at which the documents are fed from the separator must be synchronized with the speed of the transport so that as the leading edge of the document emerges from the separator, it faces an unobstructed loading gap of a carrier. This is accomplished by the use of sliding gripper pads 16 synchronized to the movement of the transport means. These pads are driven in a reciprocating motion by a cam mechanism, shown in FIG. 2. With reference to FIG. 2, synchronization of the cam mechanism is accomplished by coupling the cam shaft 24, though suitable drive means, to the document transport drive. The pads are coupled through linkage means 26 to cam 28 which is connected to cam shaft 24. Superimposed on this motion is an oscillating motion of the gripper pads sliding guides 23 which brings the gripper pads into contact with the face of the document. Oscillating motion is imparted to the sliding guides 23 by coupling the guides to oscillator cam 30 by means of linkage 31. The oscillator cam 30 coupled to the cam shaft 24 synchronizes the oscillating motion of the sliding guides 23 to the motion of the transport means. As the document moves by the gripper pads 16, it is contacted by feed rollers 19 which move the document into a carrier of the transport means. By using oscillating separator means, proper alignment between a carrier and a document is assured.

Document transport The transport means shown generally in FIG. 5 comprises an endless belt consisting of a chain of rollers 40 linked together by means of links 43. The belt is carried around the transport frame by means of tracks 41 and sprocket wheels 49. A transport drive chain couples one of the sprocket wheels 49 to the transport drive (not shown). Mounting plates 55, each accommodating three carriers 42, are connected to the belt.

A carrier which is used in this system is shown in FIG. 3. It ocnsists of a full wall 44 made of aphenolic sheet or a moldable plastic. A steel rod 46 is located along the upper edge of the carrier and is supported by three brass subhings 48. Welded to hold the document to the rod are at least two springsteel claim s 50 which will serve to hold the document in the carrier. The rod 46 supporting the springsteel clips 50 has a crank 52 formed at one end and is loaded by a torsion spring 54 at the other end so that the clips are urged against the carrier wall with sufficient force to hold the document. The operation of the carrier is as follows:

As a carrier approaches a loading station, i.e., the output of the separator 18, the crank 52 is pressed down by a roller 45 attached to the transport frame, as shown in FIG. 5. The engagement of crank 52 with the roller causes the document holding clips 50 to rise off the surface of the wall 44. In this way, the document is allowed to enter an unobstructed gap between the carrier wall and the deflected spring clips 50. The

crank then moves off the roller and the clips close under the force of the torsion spring 54 onto the document and holds it firmly in place.

Attached to each carrier is a spring strip latch 56 and a hinge means 53, as shown in FIG. 4a, the carrier being shown in a release position to be described. The function of the latch is to release the carrier over a selected stacker in response to activation of a selector 60 shown in FIG. 4b. Details of the spring strip latch 56 are also shown in FIG. 4b where the latch is shown in an unreleased position. A guide 58 is mounted on the carrier mounting plate 55 with latch 56 resting on guide 58. The latch is tripped by the use of the selector 60 utilizing an interposer type trigger. The selector will be disclosed more fully below.

With the use of clips 50 of the type described, various size letters or documents may be transported by the carrier means. The carriers, once loaded, move over a series of unloading stations 70 shown in FIG. 5, one for each stacker. These unloading stations will be described in detail below. When a carrier 42, carrying a document, arrives over an unloading station corresponding to the document's destination stacker, the carrier latch 56 is tripped. The carrier constrained at one end by hinge 53 swings down under the force of gravity to the position shown in FIG. 40 whereby the lower edge of the document is engaged by an unloading station 70. As the carrier swings down, its downward motion is restrained by stop' restrainer 64 which contacts the resilient stop 65. As the carrier moves along the transport means and moves to the top thereof, the force of gravity forces the unlatched carrier back into its latched condition, thus making the carrier ready to receive another document.

Selector A selector is shown in FIGS. 4 and 6. Its function is to trip the carrier latch 56 on signal. A selector 60 is associated with each stacker and is located on a shaft 69 running along and mounted to the transport. Each selector consists of a disc 67 to which is attached three interposers 61, 62 and 63, as shown in FIG. 6a. The set/reset lever side of the selector disc is shown in FIG. 6b. Solenoid actuators, not shown, are used to place each of the interposers in its set or reset condition. Solenoid actuators which may be used with this invention is well known in the art. In FIG. 4, interposer 62 is shown in its reset position while interposers 61 and 63 are shown in their set position. By

coupling the selector shaft 69 to the transport drive, the rotational speed of selector 60 can be synchronized to the motion of the document transport thus assuring that a latch 56 will be in position to be knocked off guide 58 as an interposer passes over the guide. When the document transport is used in conjunction with automatic sorting means, the electrical signal for actuating the solenoid actuators is derived from a control unit. An example of such a control unit will be discussed below.

Stackers Each of the stackei's, as shown in FIG. 5, consists of a simple platform 81 and ,an aligning roller shaft and guide 84. The platform 81 is mounted on a pneumatic servo piston 86 for the purpose of maintaining the top of the document stack at a common level.

Unloading stations A separate unloading station 70 is provided for each stacker, and comprises two pairs of rollers. These stations are shown in FIGS. 5 and 7. Documents are withdrawn from the carriers 42 by the first pair of rollers and 102 and fed to the stacker by the second pair 106 and 108. Roller 100 is mounted on drive shaft 103 while roller 102 is mounted on spring loaded pivoting arm 110. The second pair of rollers 106 and 108 are similarly mounted, roller 106 being located on drive shaft 109, roller 108 being mounted on spring loaded pivoting arm 104.

Though not a part of this invention, in order to completely describe the system'and its use, a generalized description of a document sorter control unit under CPU control is included. As has been described previously, such a system allows for the automatic sorting of documents as they pass over the stackers.

Sorter Control Unit FIG. 8 is a block diagram of a sorter control unit which may be used with this invention.

When the sorting is accomplished automatically under CPU control, each document must be imprinted with a destination code which, when fed to the sorter control unit 200, controls the destination of the document. This code can be placed on the document with magnetic or light sensitive ink and read therefrom by any suitable known means.

In relation to the document transport system, a document read station 204 is placed in the vicinity of the document feed area 202 wherein lies the hopper and separator shown in FIG. 1. As a coded document passes the read station, its destination information is read out and fed to a recognition and digitizing unit 206. la this manner, the information coded on the documents is digitized and fed to one input of an assembler 208.

Simultaneously with the reading of the documents a cycle counter 209 counts the number of cycles the machine goes through. For the purpose of illustration, a machine cycle will be taken as the time necessary for the separator shaft 24 to complete one revolution. The cycle number, designated the machine cycle identification number, is combined with the digitized destination code in the assembler 208 and stored in a read buffer 210. Read buffer 210, which can be either a shift register or cyclic memory, stores the combined destination and machine cycle identification number until the CPU becomes available. The minimum capacity of the buffer is variable depending on the transport configuration. If it takes, for example, twenty machine cycles for a document to arrive at the first stacker after its read cycle, the read buffer should have the capacity to store at least twenty documents. The use of the read buffer 210 allows for a time sharing use of the CPU, since, under these conditions, the CPU need be available only once every machine cycles.

When the CPU becomes available, it transmits instruction signals to the assembler 208 and to the memory address register 211 through address modifier 215 causing the contents of the read buffer to be transferred to a working area in the computer memory. The CPU now processes this information in such a way that for each document, a machine stacker is assigned in the form of a binary number corresponding to the stacker number. The processed information, i.e., the stacker number and the machine cycle identification number, is then transferred to a sort buffer. This sort buffer is basically an addressable memory.

With the system disclosed, the machine cycle identification number is used to indicate an address in the sort buffer. The address locations in the sort buffer contain the destination stacker numbers for the documents.

Since the information concerning a document which is presently at a stacker was read and stored at an address corresponding to some cycle number less than the current cycle number, a means must be provided to properly address the sort buffer at a succeeding cycle time. Such means is included in the circuitry of FIG. 8 and includes the cycle counter 209, the control cycle oscillator 226 and the address computing circuit 224.

For a better understanding of this aspect of the sorter control unit, the description thereof will be given by way of example. Assuming that it takes the document twenty cycles to pass from the read station to the first stacker, any document passing over the first stacker was read 20 machine cycles earlier and its machine identification number is 20 counts less than the current cycle count. This relation can be expressed generally by the simple algorithm:

B, the sort buffer address containing the sort information for the document arriving at the ith stacker.

C= the current cycle count.

'= stacker number.

N number of cycles necessary to transport a document from the read station to the first stacker.

S the number of cycles necessary to transport a document between successive stackers assuming equal spacing between the stackers.

On the 20 first cycle count registered on counter 209, an output signal is obtained from computing circuit 224. Since, for each machine cycle, all of the stacker numbers must be compared with the documents in the carriers, control cycle oscillator 226 is used. This oscillator has a cycle less than the machine cycle. Specifically, it must go through a number of cycles at least equal to the number of stackers during one machine cycle. In this manner, the stacker address of each document may be determined. Thus, on the twenty first cycle, with i= 1, the address in the sort buffer designated twenty will be accessed and the stacker number stored therein read out to a compare circuit 222.

A second input to circuit 222 is connected to the output of control cycle oscillator 226. When the stacker destination number, read from the sort buffer address corresponding to B (B, 20 in this example) coincides with the stacker number from the control cycle oscillator 226, a selector latch corresponding to the selected stacker is set. The set latch passes a power impulse to its respective selector solenoid which activates the respective selection mechanism Ml shown in FIGS. 4 and 6. In this manner, if the stacker number snored in address B, 20 is 1, then as the document, whose machine identification number is 20 passes over stacker 1, its carrier is released and the document fed to the first stacker.

While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

l. A document transport system comprising a. document transport means comprising an endless belt on which are suspended a plurality of document carriers each of said carriers capable of carrying documents of varying dimensions and means associated with each of said carriers for enabling the selective partial release of carriers from the endless belt,

b. means for feeding a batch of documents, one at a time, to said document carriers in a direction transverse to the direction of travel of said document transport means,

0. stacker means for stacking transported documents from said carriers and d. unloading means, for withdrawing said transported documents from partially released carriers and feeding them to said stacker means.

2. The transport system of claim l wherein, said stacker means comprises a plurality of stackers and said unloading means comprises a plurality of unloading stations, one unloading station being associated with each stacker.

3. The transport system of claim 1 wherein said transport means includes,

selector means for selectively activating said partial releasing means to position documents on selected carriers in operable relationship to said unloading means whereby documents on said selected carriers are removed from their carrier.

4. The transport system of claim 3 wherein said document transport means further includes carrier mounting plates coupled to said endless belt, hinge means for hingedly mounting each of said carriers to a carrier mounting plate, said means for partially releasing including guide means formed on said mounting plates and spring latch means coupled to each carrier, said spring latch means of each unreleased carrier being connected to said guide means, whereby disconnecting of a latch means causes partial release of its associated carrier.

5. The transport system of claim 4 wherein said means for partially releasing further includes stop means coupled to said carrier mounting plates and stop restraining means coupled to each of said carriers to limit the travel of partially released carriers.

6. The transport system of claim 5 wherein each of said carriers includes document holding clips spring bias means and means coupled to the spring bias and the holding clips for retaining said clips in a normally closed position, said meansfor retaining including a crank shaped end portion, said transport means further including means for creating a force on said crank shaped end portion to overcome the spring bias causing said spring clip to open allowing receipt of documents, removal of said end portion from the influence of the force creating means causing said clips to return to their normally closed position to retain inserted documents.

7. A document transport system comprising, a. hopper means for storing a batch of documents b. separator means for separating the documents one at a time from said batch of documents and for feeding each document to a transport means in a direction transverse to the direction of travel of said transport means,

. transport means including a plurality of partially releasable document carriers suspended from an endless belt, for transporting documents from said separator means to a stacking means,

d. selector means for causing the partial release of selected carriers from said endless belt,

e. stacker means for stacking documents received from said transport means, and

f. unloading means for removing documents from partially released carriers and for feeding them to said stacker means.

8. The transport system of claim 7 wherein each of said carriers includes a hinge and latch means, activation of said latch means by said selector means causing partial release of said carrier from said transport means.

9. The transport sytem of claim 8 wherein each of said carriers further includes spring clip means for holding said documents in said carriers.

10. In a document transport of the type comprising an endless belt from which are suspended a plurality of document carriers wherein the improvement comprises,

a plurality of carrier mounting plates connected to said endless belt, and

a plurality of document carriers connected to said carrier mounting plates, each carrier being connected to a carrier mounting plate by a hinge and latch means,

whereby release of said latch means partially releases said carrier from said carrier mounting plate.

11. in the document transport of claim 10 wherein said carriers further include spring clips for holding the documents in the carriers.

Patent No. 378 Dated February 29, 1972' Inventor(s) Marek Jakubowski It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In The Specification:

Col. 1 Line 41 after "where: delete "consists a phenolic bushings to the rod are at least two" Col. 1 Line 42 delete 'springsteel clips 50 which will serve to hold" Col. 3 Line 59 before "of a full" delete "ocnsists" insert --consists-- Col. 3 Line 59 after "made of" delete "aphenolic insert --a phenolic- Col. 3 Line 61 after "brass" delete "subhings insert --bushings-- Col. 3 Line 63 after "springsteel" delete 'clapirn s insert --clips- "Col. 6 Line 1 after "Cl nthe" delete "Z0" insert --twenty- Col. 6 Line 21 after "number" delete snored insert --st0red- Signed and sealed this 1 8th day of July 1 972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Fatents FORM F'O-IO (10-69) USCOMM-DC 60376-P69 U,S. GOVERNMENT PRINTING OFFICE: I969 0-366-334 

1. A document transport system comprising a. document transport means comprising an endless belt on which are suspended a plurality of document carriers each of said carriers capable of carrying documents of varying dimensions and means associated with each of said carriers for enabling the selective partial release of carriers from the endless belt, b. means for feeding a batch of documents, one at a time, to said document carriers in a direction transverse to the direction of travel of said document transport means, c. stacker means for stacking transported documents from said carriers and d. unloading means, for withdrawing said transported documents from partially released carriers and feeding them to said stacker means.
 2. The transport system of claim 1 wherein, said stacker means comprises a plurality of stackers and said unloading means comprises a plurality of unloading stations, one unloading station being associated with each stacker.
 3. The transport system of claim 1 whereIn said transport means includes, selector means for selectively activating said partial releasing means to position documents on selected carriers in operable relationship to said unloading means whereby documents on said selected carriers are removed from their carrier.
 4. The transport system of claim 3 wherein said document transport means further includes carrier mounting plates coupled to said endless belt, hinge means for hingedly mounting each of said carriers to a carrier mounting plate, said means for partially releasing including guide means formed on said mounting plates and spring latch means coupled to each carrier, said spring latch means of each unreleased carrier being connected to said guide means, whereby disconnecting of a latch means causes partial release of its associated carrier.
 5. The transport system of claim 4 wherein said means for partially releasing further includes stop means coupled to said carrier mounting plates and stop restraining means coupled to each of said carriers to limit the travel of partially released carriers.
 6. The transport system of claim 5 wherein each of said carriers includes document holding clips spring bias means and means coupled to the spring bias and the holding clips for retaining said clips in a normally closed position, said means for retaining including a crank shaped end portion, said transport means further including means for creating a force on said crank shaped end portion to overcome the spring bias causing said spring clip to open allowing receipt of documents, removal of said end portion from the influence of the force creating means causing said clips to return to their normally closed position to retain inserted documents.
 7. A document transport system comprising, a. hopper means for storing a batch of documents b. separator means for separating the documents one at a time from said batch of documents and for feeding each document to a transport means in a direction transverse to the direction of travel of said transport means, c. transport means including a plurality of partially releasable document carriers suspended from an endless belt, for transporting documents from said separator means to a stacking means, d. selector means for causing the partial release of selected carriers from said endless belt, e. stacker means for stacking documents received from said transport means, and f. unloading means for removing documents from partially released carriers and for feeding them to said stacker means.
 8. The transport system of claim 7 wherein each of said carriers includes a hinge and latch means, activation of said latch means by said selector means causing partial release of said carrier from said transport means.
 9. The transport system of claim 8 wherein each of said carriers further includes spring clip means for holding said documents in said carriers.
 10. In a document transport of the type comprising an endless belt from which are suspended a plurality of document carriers wherein the improvement comprises, a plurality of carrier mounting plates connected to said endless belt, and a plurality of document carriers connected to said carrier mounting plates, each carrier being connected to a carrier mounting plate by a hinge and latch means, whereby release of said latch means partially releases said carrier from said carrier mounting plate.
 11. In the document transport of claim 10 wherein said carriers further include spring clips for holding the documents in the carriers. 